SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ff84f813a53617027d82d81f6bd9160838856cfcb7bfb26dc7a23c5b152223b1' 
  AND token = 'VaOKY8GhCWyCvBxDIRywJoygDjz9RI5OZRWl7B+Q3Q0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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