SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c96d84dfbe16ad1e86c57672ec4a650fb1a4a9f1d1387e69aae95bf2deed9893' 
  AND token = 'cnRXRJJf1bNQSeestDIzclmEIlQjvIyTAbhxbrsTfxE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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