SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4aa1358120ed22e103b96e24cdfdcf88e8f30d2081a0f18dffd9b3ffe8542575' 
  AND token = 'GyioVvWmUeCcQ8EG1ocZW+Z1LjErJtfOetfEiO/TELs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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