SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bff1999c768afd4d73b43ec69f91251be36ce3608ccbcf555fb822e67083fd32' 
  AND token = 'Ks8qqkaFGJtw1onEQaonyjof5ksHh+13ztm3OWaFLaY=' 
  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"
    }
  }
}