SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fcc972b57fb46cca2ce6cd8b49b745d3fa432c5202b4a34949848bb6e42b40bc' 
  AND token = 'fgnIJi218iNBrsqfcTvaoFdiYscD4eT425gkoLqPVnM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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