SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '96b36a155a80a38c3f707530a04542f9e71b0248a804d485202418bd15fcc658' 
  AND token = 'uK9AXbWhKP6YsWAUkrUirdTlvYTjZPRbMABOJ5Zl2hc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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