SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a7787ca9c50dfdc1b0cc16b7776df3c83866da9ffd7f83dc0bf7144735e05e85' 
  AND token = 'w66OyPPKwX08dXMDESc60mnpCsOhdu8BtmTRv3DwpkI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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