SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f4b7504c3ecc652718ae6b49b132578d5174b6b4824ddde0350da653d43c956' 
  AND token = 'w0jP98uLsLGqyx/m3FlGIrnHvjkrz9WeoYu+qG+88TM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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