SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8a885a17059cad5397b812fff46f1283f4593f3293a70ae27dc6d301ed6cf4dc' 
  AND token = 'Y/tCPdomnRUflGxquB8GpF6Cf52+C6Jg+wV8zktVGxM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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