SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd633b37736dacc263005243cbfbdcf3b55e90b12d5cc0ac5574aa6191a2e1c1a' 
  AND token = 'gEalkG1IINDhwK4Wlo4pXuNFxk/mji39u8B6Efx/oCY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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