SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae29bce9582d3e22c76e33a7758513ba02aff592f00f61553d29d492b2c01023' 
  AND token = 'fCJpIGWOSYfJ87ut8S69i8Y2VI8aY01w1bESt+/sKq0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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