SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c286b3100552724787c756b1180eadb4434f235bc9aa0785bb779a10a727e79b' 
  AND token = 'DEzlZY+1wIwBTqKpRS7cICcSpjyPf1NSlPv9l/Lsz20=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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