SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3a44ea378ae21768c53c7796a5eb43e9e766c120844dba7c93bab21ec4749d41' 
  AND token = 'pktqQoTibwcZg16dgdIqVtm0n65f5vG6TXYw9voOe0A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00074

JSON explain

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