SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '439131c0dcaa4cb79afa6aac1928608ba2587779ec5172d958d040ef38afcdce' 
  AND token = 'ULrR/H82pqK+EAnyQrpbv6e/UX2/gJrA65JR9nFQSm0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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