SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '228447864d792abea817e049613b4ed1e4393222004bb12beb4547ece2d3d379' 
  AND token = '/YJ+EZYiLm6ilo6ZNDwZS9V8MVQLjnkjimbM9XAMQsI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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