SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f235c1e3de41ceeb901d53df498e90d640010f54af45d7e37805d76d6c3b71fd' 
  AND token = 'T5ShHAJYhYvFVmhxQxCvhFcGoHUnLw2MVIgKkYWEDBo=' 
  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"
    }
  }
}