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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8fe67432e1e9790f5df57fa03ce7d446fb3a0db6b2306d33da2a5919f723edfa' 
  AND token = 'IR8lQX3SZ4nRNBvKS5bRQGFY1Pe/k/w+EUYeE/6+xDM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}