SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5b90caad1318369204f94d2e94cd04a968e7d7b7e9f9c21873b8c26be25bc786' 
  AND token = 'Qfup8qiLWp2jzW58rCfnhf/m6gMD+PFjcKXVX1riEZo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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