SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '63c4d8455cbb2a06a9d8d3c1f15fdd2f9a1a4f6aae0d566f3246e87e038426ad' 
  AND token = 'vCorcS5L8STP5iLtmFJ/orZkS4CeOMvcwCCjOi/Mnz0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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