SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b85b91490f0642733e94ef11f4facfd025d029b837fc10a6c28a1f127ed7ec2' 
  AND token = 'egvPR/aBbncHLuxKPvilZDghFKMbNhfOmTVh5TiZKF4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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