SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f126bab092548d36300b546e93710953bc3eb23c8b61fbd450c0824ac15bb45a' 
  AND token = 'EhbxVJ1tbZCon3OQOzQTTIBEmodMNBmkerUYLE8d5pE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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