SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a00fd770791d29bce7ce26db4cc131ac7598e230390a3eb5590f642df656aacd' 
  AND token = 'cUwCPFVVBJmGe+d5dCjy85D6pAzsqBOFpwZl7KAwlNU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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