SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd906ee77dc19f790f38d513e8e00e38c85613835b1e6e6f1e2a6103895fb3824' 
  AND token = 'WZdLeo4cerZOMS1QlevsMnxLaW01ROl/uVI9vYnNC3w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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