SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7073f93ca1dbdb2bc8ad96b4500c9539353d65b7d811872a0ed2a91e411d1091' 
  AND token = 'K6XlkCIk9mDTSntM2itRtKo7MtEt0IExReMh+vIPZuA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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