SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '08eec00913cc20ee6afeed8adaa7bec2d2b1cd1289ba491dcefe78198ddfd93a' 
  AND token = '8PzIDS1pZCpWTOOvlrfb4KSG8Df2TN8zSP8/AJ8Cm/w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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