SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '44285753b8ff95d0ad6767fe5e46b98a568505268b273d90db8cf7cb738aa57a' 
  AND token = 'A+ZC6nudZHzvKJZ+tJPlL0YhjK6vtf0ajJ8QNRK+ZfU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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