SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ece978002573596c485be752b1b62b784dd7343440436a651de28d15124fad97' 
  AND token = 'foKzcIO4sDqT+CGqeXn+vmIudWxSN4SQzaX+Yx5e0KA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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