SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e9ab4833396eb006b8f04fda29d874fb5a8a279f20f1c85f51cb3ff3b5273acf' 
  AND token = 'J5YAZzsvBaF9FFTvinOax+gRajWTq+6jDthwQofKSNQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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