SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '24cb014b979769520f8490e19f07c3bead840d1d1d16205656df46df61dcd8ef' 
  AND token = 'P2hedHnirVaILebGuN03/OCpg4LE7qXDkU59HZXpGSk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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