SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9b99da6b67ade4b0b9409273291cb3d55156e437710d465c575f3264fd3be5a9' 
  AND token = 'HODNmON3Lw+sbyRVS0JepmvsUoSHuOEPzq2/l5/inTs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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