SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '87ea9c6293d5ee42199e050adb7735089dfa66b75bff5ab59158708ad60a343e' 
  AND token = 'H4SIuYByHQlEpFJCBeTdRYXjUwvNMTMGPRm4vQgdAlQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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