SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '797fc43c8a6051ee68dd4b821f82184d3db7650c77b0accd9d044daa32cfddd6' 
  AND token = 'uZi6A9Ylr/DiEpvhfnjKjS6GSjZ0/EBEBfKb6o9MMpo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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