SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e32bc17379a5239652ea220689ef160ab35122b302757c9c5e8377c147c60f84' 
  AND token = 'GPW+XQmNbGKU0whKuUXuiuiFnPOY7fHU4NtVqo39xEk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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