SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '196bab58528b1de0fc11607bebfec372e3ed488eff2e81f589f2c9b79bf96130' 
  AND token = '0pAGgmzvsvXEwkiVnZDcABAzIXL/um5PZsSK6FISQ4Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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