SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '35c01b94d9b985b61aa50c0cb3c1950512fb856b2f877c7684727495ba2e944d' 
  AND token = 'u5xGBfVNXmyPGYFnMwXheSN/STllxPWuBkvvZp9kmVY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}