SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b4667371ebde1debff0c5323a4487aeb0d81f050fd71f82a5ba8e22336afa790' 
  AND token = 'tIFpCSSTSArU5nEDG6uG9CircBtYEhpJk2FZXySnFlg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}