SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eae1bbda1874675032a4859c19acbda0b97bd49c2fe52143257c19b072f0e1ff' 
  AND token = 'wPL+MkRgGPlExn6mfYYRcPRGVs23y82bUvrWWjIdDf4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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