SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '89b85b1673feaa1cef8ca4b5cddbc5f11e44e80377a31b44d37f7eb2036e85cb' 
  AND token = 'ZcaV0ttA27BJaky8M4M7PPeuaeGmWfj3wHjJQ+PcrFY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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