SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '11ff9862afd54c99d55979ac3316deb38f11397ebbeccfc3d5cb9335dfda9ba3' 
  AND token = 'IstgLc7naQR5q6qQIAsm2Tt5qh9QtM32lxo7dp5Tb3Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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