SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fae57769155a2701cfbf81d8d7218100cd566fcff8142c4e3c9f4acbfc4ca81b' 
  AND token = '9zRQZyoQrR1TWQMqpNzJSej5kA+JAsEf3MkVHN4dCnE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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