SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5527a2bb512376b7bd4ff1fa258a65684adf47b7cae9412cff67bf57aecbc4f1' 
  AND token = 'zFzQRKpzrbMCxZynDcyhvk28GYUXmQ6LKaz5/4MnnlY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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