SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '035e1e103a10c8cc8eafc1a6cbf695d9601b8d35c13a88669ac3465f3b399f98' 
  AND token = 'DoXFImYD1uDh/QQP113YwVVQCpIyeFRoR2zbmrmWxfo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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