SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f5097a7e5d17f8a8f7de26a30024b6121647f88036386bf198962e06f94144d1' 
  AND token = 'HXpMWx9QY17GutjetbvM/zAS2TV7dHyqLUMwFPkURMQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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