SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f8fbaa47bbb413c50bc18bc1bee970f3b9dec02de75e1053807536ad5dd0716' 
  AND token = 'D24n8kWaLreTm9mlQzdOWSL+kcwF3TAf+kKIFK9cqFs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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