SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2dabb19bf958f5662b302bfa383a9eeea3361940dadaa252015f92acc43e0083' 
  AND token = 'sg2GMantzjW33Ziy/ggi+UKFEyLlWmi8vWm/m9WkrB0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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