SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cb328a2727aab9c65b8199d4c4d3e350035b6848d7cef0c1994d8bf9805371b5' 
  AND token = 'P/pLOuT3cGSsDjn3DZS8QzNvGkp95Y1vPpRPLPEVhz4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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