SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f90404c9783d88b8c448314d741e0a75fdb67264e1401968a292efeef6bd7d7' 
  AND token = 'coLsro98e8Ut1eyj+WuZyUiDDm2E4GQkhQgPHvAvkpU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}