SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f944167b298eec5992611cf3f0168dcd4b5fef654b071c0407caae07ab7fe1d0' 
  AND token = 'N29cXVXu3vCUoGscmKLUiuoutgChwZqJ2+oSx0jeD/g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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