SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ecd993bc93759d5b36c0614016a90817f1651085b38a898c08e169b55b077185' 
  AND token = 'c8K7RouyLqgsHITBDWX7SzdqL8ZtRXVHMsSrEdt0xs8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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