SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a726567ab06839d7f062a2a7fb7f736d4e59646b7f6e900d80575758811cdb12' 
  AND token = 'MgXY7rg6pT+jg+gVcJ4ktUeew2daog1UlihLBZv9YXo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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