SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9ba325250a9c9d3d388ca66545750935bd2ea5178635bbeef51bca18453b2cf6' 
  AND token = 'K/rnYW6usY/zBiDzSRDkWPK2Et63Q9qymGUrHOPVOi4=' 
  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"
    }
  }
}