SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3e82f08823007d91d7695318e8bd16ff77c3fe80c17c188025cca0a92833c3e3' 
  AND token = 'QgJEfAVsTJFX+bfOQFXYwW/LEU+VfMR0eaCqJrbbNIA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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