SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7b42a3145676ff7050381df33ffc608ac3bd8ce2c4de451eb552669b606a7894' 
  AND token = 'XzF/o8Luu3/EnmAgW0ejpG3iowS9qYV0SREO5ZUa3dw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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