SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c9de9e0f7579bdf00b08662d4f217b04619b180aea0759902acc7d67cb7c550c' 
  AND token = 'w8P4nqHz6paiFy61PrtJHsB9ydCrJn3HitJNemRHG5M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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