SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dd97b207858cc92d0742d85a39315d81601b0ab9140c23c1fdd7248aa7312b31' 
  AND token = 'Uzi3l+xNMeGCzRHA2/mEbI61V7W4fOKhueuk/RZf5kI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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