SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7da6285af7dc20cad7c92efc9f0bd36568ffc1a8a6dcb9c0fdcea5bdc3cf2a28' 
  AND token = 'Ksy4D0BBncIgTc964iwS6Nv8ZpESKMhtI7LzQOei7BI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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