SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f9b3bd889bd3353955b13d8a8b8aec1dbf1c250a8b469deec0fc996ef3a7d615' 
  AND token = '/j1OUYOgL+n5I6eqpv4h2JJL7GkvyLXbpewL+V8zpxc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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