SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '97dee6749cd291ab4c3b5d6e249fd32195a5456de53f565c7ebaeeed428f8ee3' 
  AND token = 'T9GMJOXqw922PQGZ7Bm6Ecs2oQ7zPSlEGdNnM8iwHj8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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