SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '26f6322b28ab2fba2069ae6b7b21ed238896dec0c7b0c0a008050e8431c78fb3' 
  AND token = 'ZBrjIF0yWXgehwBYyis7rOOUMZ90ONx51z5VjCQlSFc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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