SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e1f045d4476b3417f13ccbb5ced226c754b196aaf0335fe781814d0d8b420cc6' 
  AND token = 'JpP7Fp6Bq7ea8q9LxF8OBOhggPgxCDY+KQdtvNtY5KA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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