SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c6a1a7c376cb8aa6df43e2f745446eae33f579f7e98b1da27c19b120c662002d' 
  AND token = '8kJHy9/O5cG4qqQXSYmMIIA2viS9+KtgCv/K9sGYuNw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00108

JSON explain

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