SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb0a646deee62e29115f4e1ec1ea7981aac73d75382542f888ac8bd70946e4f3' 
  AND token = 'C2SBlxRBl4HXwkK47oH8cW31CBAeZs6dPX082dsEJ3c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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