SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '61224077b1fc6fe28c1f4693f504b58db0bc20ee2c9da12b87180a202e3d5678' 
  AND token = 'u7xG/vuGfm0Dc+s9oLFUM0stupVaDLILGyKcORovPpA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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