SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '598b41fcfbbce9868ed36c48d55fb722b1f728bc474c5f6e4a45f9dd9fe1e2c8' 
  AND token = '+kLJfnH2a9mPsJKUckohuVOx+mqG7qior8XKv6YkQPw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}