SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2a5964175ab3c0cc5e211ffad772daedb61134f430fe87f40ff73bff98c147a9' 
  AND token = 'v7esb7O6+dCEtYJY0tQqbiTOlJaas4Rjh0yE3kkShO0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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