SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e004b1e1a99ffdfc6ea757147ebced10db74d1fdc02f776fb29eb016efed9de8' 
  AND token = 'BimpobkXTsaOwA8XOEUAk+ssNpDM9efsb9bARCBWQdw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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