SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd391bced17a3a5f9b62ef9cf406f405227bfc6b8749ad761d765e73695374d00' 
  AND token = 'XdZFlzxBaHPiPk/SFkcnOrEUg4MUTsf/u2V3NUpYPnE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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